Action users number confusion
The number shown is called a user count. A user being defined as a data block (or object) in blender.

A new action will have one user, adding a fake user by clicking the 'F' button makes it 2 users, to get a third user you need to link it somewhere else, like to another object, a strip within the nla editor or an action constraint.

By dulicating an object with AltD (known as a linked copy) the new object will also be linked to the action. If this is the case then you may be importing the duplicate into unity not the one you added the new action to.